In effect Biden just gave the okay for China to invade Taiwan.
It should be noted that Taiwan has a highly sophisticated engineering capability and nuclear reactors which can produce fissile fuel. They have the capability to produce nuclear weapons but did not as they have relied on the USA nuclear umbrella to protect them. They made a horrible mistake.
Could Taiwan defeat China in a nuclear war? No they could not. Could Taiwan wreck devastation on China if armed with nukes? Yes they could, thus China would not attack.
I forgot to add that France and the United Kingdom have nuclear forces that can not defeat Russia but that is somewhat irrelevant. They can destroy Russia as a functioning society and they would also be totally destroyed.
It is that simple. A nuclear nation of overwhelming superiority will not attack a nation with one nuclear sub that can destroy them as a functioning society. One sub can and we have many, France and England have a few.